What do the + and – versions of a preset mean?

All our film presets have one or more variants, labeled +, ++, -, or –. These presets emulate the look of that film when underexposed (-) or overexposed (+). Typically, underexposed versions (-) will have less contrast, lower saturation, and darker colors, in addition to faded shadows, increased grain, and some color shifts. Overexposed versions (+) will have higher contrast, more color saturation, and some tonal shifts.